The invention relates to a programmable fast Fourier analyzer device realized with MOS microprocessors, suitable to carry out tasks connected with measurements, control and control engineering such as sound and vibration analysis, and the prevention of the fatal breakdown of equipment.
Several types of compact /bench-type, portable/ fast Fourier analyzer devices are allready known. In respect of constructional design, these can be divided into three basic groups: 1. A system of circuits built up of the elements of one of the groups of digital electrical circuits /e.g. TTL, ECL/ with application of a fast bipolar multiplier-accumulator. In order to establish connection to the control means, a cathode-ray-type display and other digital external elements, comprising microprocessors are applied. 2. Circuit system realized with a bit-slice bipolar microprocessor. Such processors are, on account of their high operation rate, also capable to carry out measurement-data acquisition, fast Fourier analysis, control-operation for the cathode-ray tube displaying the results, and the connection with the control means. For example, the narrow-band analyzer of the firm Bruel and Kjaer /Denmark/ type 2033 comprises a bipolar microprocessor. 3. Some instrument manufacturing firms--in order to supply their own instruments--possess a special own production-technology for the manufacture of MOS integrated circuits, having designed special integrated circuits suitable for digital filtering and for a FFT analysis. Such firms exist mostly in the United States and in Japan. For example, the spectrum analyzer type 3582A of the firm Hewlett-Packard /U.S.A./ is manufactured, using a microprocessor designed and produced by themselves.
A fast Fourier analyzer built up of the elements of one of the groups of digital circuits contains a great number of parts. Its drawback is that the development takes a long time connected with a great amount of expenses. Its further drawback is that it is "hardware-oriented", i.e. after the development has been finished, it can not be adapted to the special and variable requirements of any users without redesigning and alteration of the program. Its advantage is the high signal processing rate. Fast Fourier analyzers built around bit-slice bipolar microprocessors contain fewer parts than the former one, but they are built up of expensive parts and their development is very time-consuming. A further drawback is their lower signal processing rate, as compared with that of the former one. Their advantage is that their structure is not rigidly hardware-oriented and a limited possibility of programming can be undertaken by the manufacturer or by the user. The drawback of fast Fourier analyzers containing special MOS integrated circuits is their low signal processing rate, further the fact that such circuits are not available for anybody except the manufacturer. The aim of the present invention is the development of a fast Fourier analyzer which contains microprocessors prepared by the generally applied MOS technology and which can--by means of a universal keyboard--be adapted by the user to the individual task. The apparatus according to the invention as well as its development is more inexpensive and can be more flexibly adapted to the requirements of the fields of application than the known devices.